(a) Field of the Invention
The present invention relates to a system and method of detecting drowsy driving, and more particularly, to a system and method of detecting drowsy driving based on a steering torque from among a plurality of driving patterns.
(b) Description of the Related Art
Drowsy driving is a cause of four out of ten expressway traffic accidents, thus, a system that prevents traffic accidents due to drowsy driving is necessary.
A system has been recently developed for monitoring a state of a driver and the system generally evaluates a state of the driver by analyzing a driving pattern, an image of the driver, and a bio-signal. In addition, a system for detecting drowsy driving based on the driving pattern may be advantageously implemented only with control area network (CAN) data without using an imaging device (e.g., a camera) or an additional sensor.
A technology of detecting drowsy driving based on a driving pattern evaluates a state of a driver using various signals obtained within a vehicle such as a steering angle, lateral displacement, a vehicle speed, and the like, and a driving characteristic, based on which a stale of a driver may be inferred, is detected by combining those signals.
The most widely used characteristic in the related art is a steering angle dead-band. The steering angle dead-band refers to a steering pattern in which a steering angle is maintained at approximately 0 degrees for a predetermined period of time and then is rapidly changed. When a driver drives while drowsy, the driver maintains a steering angle of approximately 0 degrees for a predetermined period of time and then suddenly steers the vehicle while waking up, so that the steering angle dead-band is used as a characteristic of drowsy driving.
However, when the drowsy driving is determined based on the steering angle dead-band, since a change in a steering angle is substantially small during normal (e.g., when no sudden steering movements are experienced) driving while monotonous high-speed driving which is an operation condition of most detection logics of drowsy driving, it is impossible to estimate when the driver becomes drowsy even though no change in a steering angle is experienced.
Further, since a rapidly changed steering pattern is experienced after dangerous drowsy driving, the rapidly changed steering pattern is insufficient for the purpose of preliminary warning of the detection logic of the drowsy driving. Further, in many cases, when a driver wakes up, when a situation is not dangerous, there is no rapidly changed steering, and thus, the steering angle dead-band is not generated.
Accordingly, the existing steering angle dead-band characteristic has a disadvantage in that drowsy driving is detected after a dangerous situation is already generated, and it may be difficult to distinguish between general drowsy driving and normal driving.
The above information disclosed in this section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.